Home Secretary Theresa May today insisted she had "unambiguous legal advice" from the government's lawyers about the deadline to deport Jordanian terror suspect Abu Qatada.

May backed David Cameron's comments yesterday that the Home Office "checked repeatedly" with the European Court of Human Rights (ECHR) about when the deadline expired and was "very clear" about the date.

The confusion, which centres on whether the three-month appeal deadline from the court's original decision on January 17 expired on the night of April 16 or 17, risks seeing the radical cleric freed and back on Britain's streets within weeks.

May said she was given "unambiguous legal advice" on the deadline from lawyers in the Home Office and the Foreign Office.

She also told MPs the decision to arrest Qatada on the morning of April 17 was also based on the court's rules, associated guidance notes and precedent.

May refused to directly answer whether she had any email or letter from the court saying when the deadline was.

"The decision as to whether or not the deadline has passed is taken by the panel of judges at the Grand Chamber," she said.

"They are the arbiters.

"It's up to the panel of judges as to what decision they take."

May added she was right to act when she did and "take the first opportunity to deport Abu Qatada", once described by a judge as Osama bin Laden's right-hand man in Europe.

The Home Secretary admitted there was "speculation about mixed messages on the Monday night (April 16) and the Tuesday morning", but insisted the advice she was given was clear.

"All the advice I've been given has been the same," she added.

May denied that the row over the human rights court's rules meant efforts to deport Qatada had descended into farce.

She said it was not a farce for a minister to receive unambiguous legal advice and then take action to deport Qatada as quickly as possible.

May also said she had "a dozen letters", all relating to other cases, which backed the Home Office interpretation of the deadline.

"The advice I have received has been consistent. The advice I have received remained consistent and remains consistent until this day."

Mrs May also told MPs on the Commons Home Affairs Select Committee that the Government has written to Europe's human rights court setting out why Qatada's appeal should fail.

It was out of time, the original ruling did not depart from case law and no general interest reasons were raised, she said.

She added that there was another reason highlighted in the Government's response, but gave no details.

May added: "I'm very clear that the assurances we've received will enable us to deport Abu Qatada."

Asked by Mark Reckless why she was putting an intergovernmental agreement with the Council of Europe, which runs the court, above British courts that have said Qatada should be deported, May said the Government "abides by the law".

"The UK Government abides by its international treaties and we do not break our international treaties," she said.

"The UK Government operates according to the rule of law.

"Our courts are clear that the law requires us to abide by our public guidance and to apply the guidance consistently."

She said deporting Qatada immediately would mean giving him 72 hours notice, possibly leading to his lawyers being granted an injunction, risking further court orders banning the Government from deporting him.